It could be due to their pure and selfless nature. In the novel, the saints might have gone through some kind of spiritual purification process. Their selfless deeds and noble characters make their magic power omnipotent. They use their magic not for personal gain but for the greater good, like protecting the world or helping the weak. This kind of positive energy may be amplified into omnipotent magic power.
There could also be some other characters related to the saints, like their apprentices or followers. They may inherit or be influenced by the saints' omnipotent magic power. Maybe there is a young character who is being trained by a saint and gradually shows signs of having a very powerful magic due to the saint's teachings.
Antagonistic characters are also likely to be important. They could be those who envy the saint's omnipotent power or those with their own motives that conflict with the saint's use of power. Their interactions with the saint create conflict and drive the story forward.
The plot of this light novel is likely centered around the concept of omnipotent magic power. It could involve the saints using their power to solve problems, face challenges, or even face moral dilemmas. There may be antagonists who are either threatened by or trying to take advantage of the saints' power.
In many such fictional settings, the concept of an omnipotent magic for a saint might be related to the balance of the world in the story. Her magic power could be omnipotent to counteract great evils or restore order. For example, if there are dark forces threatening to destroy the world, her magic is the only thing that can stop them, thus it is made omnipotent by the story's design.
A common theme is power and responsibility. Since the saint has omnipotent magic power, she has to decide how to use it. Another theme could be isolation. Her great power might set her apart from others, making her feel lonely at times.
Many novels have saints, minor saints, and great saints. If you want me to recommend a novel for you, you can provide more specific information, such as the type of novel, plot, and so on. I'm very happy to recommend a novel that suits you. It's great! I recommend the following novels to you, see if you are interested:
1. "Journey to the West: Starting From Zero"
2. "The Great Sage, Bring Me to Immortality."
3. Legend of the Reborn Sage
4. " Sign in to the Sage Rank at the beginning of the game."
5. "The Great Sage's Return: Subverting the Universe."
6. " The Era of the Global Saints."
7. The Grand Sage of the Beginning.
8. Journey to the West: The Golden Crow Grand Sage
9. The Great Sage from Heaven
10. Hanguang Great Sage
I hope the above recommendations will be helpful to you. If you have any other needs, feel free to ask. I will try my best to recommend more good novels for you. I wish you a happy reading!